Ann: West Arunta Project - Luni Assay Results, page-112

If the sell off has anything to do with the news, which it quite possibly doesn't given overall market behaviour at present.
The best explanation as reaction to the news is on the grades reported by the twin diamond hole vs the RC hole.

For the high grade
RC Diamond
40m @ 3.1% 31m @ 2.4% ( ~ 77% difference)

For the larger interval
RC Diamond
97m @ 1.6% 150m @ 0.6% (residual grade of low grade zones excluding high grade = RC - 0.64%Nb & DD- 0.42% Nb) ~ 0.65% difference)

Some view RC as a less reliable method of sampling (e.g. loss of sample fines through excessive dust creation, potential contamination from damp/wet samples etc) than diamond and this first twin diamond hole seems to downgrade the RC twin 75-65%.

However assigning any significance to this initial one off variance is premature i.e and deciding which sampling method is giving a more accurate grade. Quite a few more twin diamond holes are needed because:

1) We have one twin for comparison which is not yet statistically significant
2) We are drilling an ore body enriched by weathering processes and considerable short range variability can be expected- e.g. Nb is in discreet grains that could vary considerably in size, and one could expect fractures and jointing (greater water permeability) could influence grade strongly over very short ranges.
3) One has to be aware of the very different sampling basis provided by RC, in this case 5 & 3/4 inch diameter hole vs 3 inch HQ diameter core. On a plain volume basis RC is giving 5 times the sample volume of the diamond hole. But when it is considered that the HQ core is mostly split into two with one side retained and the other side assayed (crushed and split) while the entire RC interval is split with the split assayed the RC is 10 times the sample volume of the diamond core. This is a much more representative sample of the ore body than that given by the diamond core.

Upshot of point 3 is if the RC is drilled well and known issues are effectively dealt with RC can actually give a much more representative sample /grade with less variance (within and between holes) than diamond core.


Todays one day bear (-20%) off the intraday high is an overreaction and if the next few days are a drift down this is a great buy opportunity.